1. Field of the Invention
This invention relates generally to writing instruments.
2. Prior Art
Conventional straight writing instruments such as ink pens, ball point pens, and pencils have straight and narrow cylindrical bodies. The lower portion of a typical writing instrument is arranged to be held between the tips of the thumb, index finger, and middle finger. The upper portion of the pen is arranged to rest between the bases of the thumb and index finger. The narrow round bodies of conventional writing instruments require a relatively firm grip to prevent them from slipping, and to push the pen onto the writing surface. Therefore, they are uncomfortable to use for long periods.
Many other alternative writing instruments that attempt to provide a better grip are known among the prior art. U.S. Pat. No. 336,540 to Wyttenbach and U.S. Pat. No. 340,382 to Smith each disclose a pen with a short tip and a pair of bifurcated arms extending from the tip. The arms rest on opposite sides of the index finger. The tip is round and suffers the same gripping problems as a conventional pen. U.S. Pat. No. 4,127,338 to Laybourne discloses a fingertip pen with a ring at an upper end for being positioned forward of the middle joint of the index finger. A curved depression on a top side is arranged for supporting the tip of the index finger. However, the tip is round and suffers the same gripping problems as a conventional pen.
U.S. Pat. No. 5,391,010 to Gorbunov discloses a pen with a ring arranged for being positioned around the base of the index finger. It includes a depression at the tip for supporting the tip of the index finger, but the depression is curved about an axis which is transverse to the axis of the pen. The index finger can thus slip sideways in the depression. The sides of the pen are cylindrical, and suffers the same gripping problems as a conventional pen. U.S. Pat. No. 5,885,018 to Sato discloses a pen with a round shaft attached on the lower surface of a curved plate. A partial ring is formed at the top end of the plate for gripping the finger forward of the middle joint. The shaft is about the diameter of an ink tube inside a conventional ballpoint pen. The plate is much wider than the shaft, which is so narrow that it cannot be gripped securely. The fingers can only grip the top and bottom surfaces of the thin plate.
U.S. Pat. No. 6,161,974 to Nakagawa discloses a pen with a ring. The axis of the ring is transverse to the axis of the pen for passing the index finger, which is held in a fully curled position. Only the thumb and the index finger are available for gripping the tip of the pen. Further, the tip is cylindrical, and suffers the same gripping problems as a conventional pen. U.S. Pat. No. Des. 246,904 to MacIntosh discloses a fingertip pen with a cylindrical tip, a concave upper body, and a ring attached to the upper body. The tip is round and suffers the same gripping problems as a conventional pen.
The objects of the present ergonomic pen are:
to require less gripping force to hold for improved comfort;
to securely cradle the tips of the thumb and fingers for preventing slipping;
to be pressed onto the writing surface by the base of the index finger; and
to cover the writing tip when not in use.
The present writing instrument is comprised of an elongated body with a writing point at the lower end, and an upper end for supporting the base of the index finger. Arcuate arms extending up from the upper end of the body are arranged for being positioned on the sides of the index finger. A concave front groove with an arcuate cross section is arranged along the front side of the body, and curved about an axis parallel to the axis of the body for cradling the tip of the index finger and preventing it from slipping sideways. The upper end of the front groove is flared into the upper end of the body for cradling the lower side of the base of the index finger. The lower end of the front groove is rounded for preventing the index finger from slipping downward. Concave side grooves with arcuate cross sections are arranged along the sides of the body, and curved about axes parallel to the axis of the body for cradling the tips of the thumb and middle finger to prevent them from slipping forward. The body has a generally trapezoidal cross section wherein the front is wider than the rear, and the sides taper toward the rear. Forwardly protruding ears are arranged between the front and sides for being pinched between the index finger and the thumb, and between the index finger and the middle finger. A cap is movably attached to the lower end of the body. A knob on the rear side of the body is movable upward to retract the cap and expose the writing tip, and movable downward to extend the cap to cover the writing tip.